Medical Dictionary Definitions A-Z List

Medical Dictionary Definitions A - Z - «G»:

Galton, Sir FrancisGalton, Sir Francis: English advocate of eugenics, the idea of improving the physical and mental makeup of the human species by selective parenthood.
Galton coined the word "eugenics" to denote scientific endeavors to increase the proportion of persons with better than average genetic endowment th...

GameteGamete: The sperm or the egg. Each human gamete
normally has 23 chromosomes, the haploid number of chromosomes, half the number of chromosomes contained in most types of cells in the body....

Gamete intrafallopian transfer (GIFT)Gamete intrafallopian transfer (GIFT): A technique in which
the male and female germ cells required to begin formation of a human
embryo are injected into a woman's fallopian tubes of the female for
fertilization. This technique is one of the methods doctors use to
overcome infertility, the inab...

GametogenesisGametogenesis: The development and production of the male and female germ cells required to form a new individual.
The male and female germ cells are called gametes. The gametes in human males are produced by the testes, two globe-shaped reproductive organs just below the penis. Male gametes are wh...

GametophobiaGametophobia: An abnormal and persistent fear of being married. Sufferers of gametophobia experience undue anxiety even though they may rationally realize that the married state itself poses no threat to them. They may fear the challenge of living with another person and the responsibility of reari...

Gamma hydroxybutyrate (GHB)Gamma hydroxybutyrate (GHB): Known in Europe as Gamma-OH, gamma hydroxybutyrate is a colorless and odorless drug used illicitly for "recreational" purposes and for "date rape." GBH is a central nervous system depressant. It tends therefore to increase sociability and function as something of a trans...

Gamma knifeGamma knife: A type of radiosurgery (radiation therapy) machine that acts by focusing low-dosage gamma radiation from many sources on a precise target. Areas adjacent to the target receive only slight doses of radiation, while the target gets the full intensity.
The gamma knife may be used to treat...

Gamma rayGamma ray: High-energy electromagnetic radiation emitted by certain radionuclides when their nuclei transition from a higher to a lower energy state. Gamma rays have high energy and a short wave length. All gamma rays emitted from a given isotope have the same energy, a characteristic that enables s...

Gamma-OHGamma-OH:A European name for gamma hydroxybutyrate (GHB), a colorless and odorless drug used illicitly for "recreational" purposes and for "date rape." GBH is a central nervous system depressant. It tends therefore to increase sociability and function as something of a transient antidepressant.
Some...

Ganglia, basalGanglia, basal: A region located at the base of the brain composed of 4 clusters of neurons, or nerve cells. This area of the brain is responsible for body movement and coordination.
The groups of neurons most prominently and consistently affected in Huntington disease -- the pallidum and striatum...

GanglionGanglion: The celebrated 2nd century Greek physician Galen ((c. 130-201 A.D.) who lived and worked in Rome first used the word ganglion to denote a nerve complex. Ganglion still is used to refer to an aggregation of
nerve cell bodies. Another use of the word ganglion is for a tendon cyst that most ...